1: 3-chloro-benzenecarboperoxoic acid / dichloromethane / 0 - 20 °C 2: 1,2-dibromo-1,1,2,2-tetrachloroethane; alumina-supported potassium hydroxide / tetrahydrofuran; tert-butyl alcohol / 8 h / 20 °C 3: boron tribromide View Scheme